Various vacuum units and systems have been developed and used for picking up various types of material. In specific applications, for example, vacuum units have been used for excavation, for example, where removal of the excavated material was difficult to accomplish by other methods or where the excavation had to take place where damage to equipment, such as buried equipment, was a significant risk if alternative methods of excavation were used. Further, relatively large vacuum units have been mounted on a truck, and vacuum trucks have been driven to sites where excavation has been needed or where material needed to be picked up. For example, vacuum trucks have been used to excavate around buried utilities such as pipelines buried in the ground, where shutting down the pipeline would be a significant detriment, where excavation with other means, such as a back hoe, would have a greater risk of damaging the buried utility or pipeline, impose a safety risk to workers, or a combination thereof.
Still further, water has been used to break up material (e.g., earth) at an excavation site where the material is being picked up by a vacuum unit or system. Water systems have been mounted on vacuum trucks for this purpose, and have included, among other things, a water tank, water pump, water conduit that extends to the excavation site, and a water nozzle that is hand guided at the excavation site by an operator. Vacuum trucks with water systems have been referred to as hydrovac trucks, for example. Even further, air has been used to excavate material as a replacement for excavation water. Further still, excavation systems that used water often resulted in the material becoming overly wet (e.g., mud) which has made the material poorly suited to use immediately to backfill the excavation site when the work that required the excavation was completed. On the other hand, excavation systems that used air often created excessive dust and were not as effective as water at excavating certain types of material. Needs and potential for benefit or improvement exist for vacuum units and vacuum trucks that overcome these and other deficiencies of the prior art.
Even further still, various components of vacuum trucks have been powered by an internal combustion engine mounted on the truck (e.g., that also drives the truck) but it has been difficult to transfer power from the engine to the various components that need the power. In many instances, different components had to be located on the truck where those components could get power from the engine rather than at a more convenient location, for example, relative to other components on the truck. Needs and potential for benefit or improvement exist for power transfer systems on vacuum trucks, and trucks with such power transfer systems, where the power transfer systems overcome these and other deficiencies of prior vacuum trucks and prior power transfer systems used on vacuum trucks. Needs and potential for benefit or improvement exist, for example, for power transfer systems on vacuum trucks, and trucks with such power transfer systems, where the power transfer systems power a vacuum system, a compressed air system, a boom, one or more auxiliary systems, a water system, or a combination thereof.
Moreover, vacuum trucks have been used where the engine powered the vacuum system and the speed of the engine has been varied or adjusted to control suction pressure within the vacuum system. Where the engine has been used to power other systems or components of the vacuum truck, however, changing the engine speed has changed the speed, power, or both available to these other systems or components of the vacuum truck. This has made it difficult to control the suction pressure and other systems or components (e.g., independently) to optimize all systems and components of the vacuum truck. Needs and potential for benefit or improvement exist, for example, for power transfer systems on vacuum trucks, and trucks with such power transfer systems, where the power transfer systems provides for adjustment of the vacuum system (e.g., blower speed) without changing the engine speed or that provide for changes in engine speed without changing the suction pressure.
Additionally, vacuum units have been equipped with a suction relief valve that opens to relieve the vacuum. For example, an operator of a vacuum truck has been provided control of a suction relief valve that the operator can open quickly to relieve most or all of the vacuum in the event the vacuum is having a deleterious effect. Prior art suction relief valves on vacuum units, however, have been either fully open or fully closed and were not suitable to make fine adjustments to suction pressure, for instance, to avoid a deleterious effect, for example, without disrupting excavation of the material. Needs and potential for benefit or improvement exist for suction relief valves for vacuum units and trucks and for vacuum units and vacuum trucks that overcome these and other deficiencies of the prior art, for instance, that provide the operator with more control of the suction pressure.
Furthermore, vacuum trucks have been built with the boom mounted approximately in the center of the vacuum truck relative to the left side and right side of the truck. Further, the reach of a vacuum truck has been limited by the length of the boom. Needs and potential for benefit or improvement exist for vacuum trucks that allow the truck to be used to excavate farther from the center of the truck, for example, without increasing the length of the boom, for instance, while providing appropriate structural support for the boom. Needs and potential for benefit or improvement exist for vacuum trucks that overcome these and other deficiencies of the prior art.
Further still, vacuum trucks have been manufactured with various debris tanks that hold the material once the material has been excavated. These debris tanks have been dumped in a number of ways to empty the debris tank. In some embodiments, debris tanks have been tipped to empty the material and in some embodiments debris tanks have been equipped with a sweep system or blade that moves the material (e.g., mud) within the tank. See, for example, U.S. Pat. Nos. 6,547,964, and 6,607,666 (both Rajewski) and U.S. Patent Publication 2013/0149089 (Harms JR). Such systems, however, have been, among other things, complex, expensive, high maintenance, and time consuming. Needs and potential for benefit or improvement exist for vacuum trucks and debris tanks for vacuum trucks that overcome these and other deficiencies of the prior art. Even further, needs and potential for benefit or improvement exist for vacuum trucks that have debris tanks that are capable of emptying the material without: tipping, use of an internal sweep, or use of an internal blade; that are structurally suited for the loads imposed (e.g., to support other components such as the boom, to withstand the vacuum, etc.); that utilize available space on the truck efficiently; that are relatively easy and inexpensive to manufacture; that are easy to maintain; that utilize structural components efficiently; and/or that provide for efficient and convenient transfer of the excavated material back into the excavation site when the work that required the excavation has been completed.
Room for improvement exists over the prior art in these and other areas that may be apparent to a person of skill in the art having studied this document.